1. Field of the Invention
This invention relates to a mold closing unit for use in an injection molding machine for synthetic materials, comprising a device for moving at least two first identical parts of an injection mold, each of them mounted on a swivel arm, which is rotatable around an axis parallel disposed with respect to the closing direction, whereby the first parts of an injection mold are transferred alternately into at least one parting plane in the mold stressing chamber between the mold carriers of the mold closing unit on a transfer path vertically disposed with respect to the closing direction, for production of an injection mold.
2. Description of the Prior Art
German Published Patent Application 40 08 310 discloses a unit in which the parts of the injection mold are swivelled into the parting plane. The parts of the injection mold can be swivelled around a separate axis, whereby each part is individually swivelled. An axial displacement of the two parts against one another is necessary, so that one part can be moved into the parting plane inside the mold. As a result, the moldings can be taken out relatively quick from the injection mold, however, a separate drive to make the movement possible is required for each first part of the injection mold, which means that the removal position is changed for every injection cycle. However, since it should be avoided to touch the moldings during the removal process, the changing position is or no special importance in this case. The costs involved for the removal of the moldings from the mold cavity are increased in so far as separate drives are required for each first part of the injection mold.
A further installation for removal of moldings from the mold cavity is for example known from European Published Patent Application 359 013 A2. For removal installations of that kind it is, however, basically necessary, that a grab of the removal installation dips into the space between the stationary and the movable mold carrier, in order to withdraw the moldings from the mold cavities. That is why the opening width between the two mold carriers is mainly determined by the size of the grab to be introduced. However, the larger the necessary distance between stationary and movable mold carrier has to be for removal of the moldings, the more time is needed for bringing both mold carriers into the position with the required distance. Practice shows that at causes time and again problems, if the grab does not immediately get properly hold of the moldings during the removal process, which aggravates the circumstances additionally. This over and over again results in idle time, which counteracts a quick and troublefree production.
German Patent 12 68 365 furthermore discloses a system which is utilized for two-color injection. To this end the first parts of the injection mold are turned inside the injection mold around an axis disposed transversally with respect to the closing direction. It is possible to support the turning movement for example by an eccentric to the effect that the mold chambers are in the corresponding positions desired. However, the only purpose of this invention is, to make the mold accessible to the two-color injection and it is not possible to carry out moldings from the injection mold with this installation, since such a disposition of the swivel axis transversally to the closing direction, still would mean that the total opening distance had to be covered by the mold closing unit.